diff --git a/UpdateLog.md b/UpdateLog.md
index 4f4a7cd9c..30405f3d9 100644
--- a/UpdateLog.md
+++ b/UpdateLog.md
@@ -2,6 +2,31 @@
 
 开发版本. 频繁更新, 不保证高稳定性
 
+## `0.12.0`  *2020/1/19*
+### mirai-core
+1. 监听消息时允许使用条件式的表达式, 如:
+```kotlin
+(contains("1") and has<Image>()){
+    reply("Your message has a string '1' and an image contained")
+}
+
+(contains("1") or endsWith("2")){
+
+}
+```
+原有单一条件语法不变:
+```kotlin
+contains("1"){
+
+}
+
+"Hello" reply "World"
+```
+
+2. Message: 修复 `eq` 无法正确判断的问题; 性能优化.
+3. 简化 logger 结构(API 不变).
+4. 事件 `cancelled` 属性修改为 `val` (以前是 `var` with `private set`)
+
 ## `0.11.0`  *2020/1/12*
 ### mirai-core
 - 弃用 `BotAccount.id`. 将来它可能会被改名成为邮箱等账号. QQ 号码需通过 `bot.uin` 获取.
diff --git a/gradle.properties b/gradle.properties
index 0ef7411ee..7b2a54474 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,7 +1,7 @@
 # style guide
 kotlin.code.style=official
 # config
-mirai_version=0.11.0
+mirai_version=0.12.0
 kotlin.incremental.multiplatform=true
 kotlin.parallel.tasks.in.project=true
 # kotlin
diff --git a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/event/MessageSubscribers.kt b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/event/MessageSubscribers.kt
index 51a77ec48..43d9ab6a3 100644
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/event/MessageSubscribers.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/event/MessageSubscribers.kt
@@ -111,6 +111,9 @@ inline fun Bot.subscribeFriendMessages(crossinline listeners: MessageSubscribers
     }.apply { listeners() }
 }
 
+
+typealias MessageListener<T> = @MessageDsl suspend T.(String) -> Unit
+
 /**
  * 消息订阅构造器
  *
@@ -121,130 +124,312 @@ inline fun Bot.subscribeFriendMessages(crossinline listeners: MessageSubscribers
 @Suppress("unused")
 @MessageDsl
 class MessageSubscribersBuilder<T : MessagePacket<*, *>>(
-    val subscriber: (@MessageDsl suspend T.(String) -> Unit) -> Listener<T>
+    val subscriber: (MessageListener<T>) -> Listener<T>
 ) {
+    /**
+     * 监听的条件
+     */
+    inner class ListeningFilter(
+        val filter: T.(String) -> Boolean
+    ) {
+        /**
+         * 进行逻辑 `or`.
+         */
+        infix fun or(another: ListeningFilter): ListeningFilter =
+            ListeningFilter { filter.invoke(this, it) || another.filter.invoke(this, it) }
+
+        /**
+         * 进行逻辑 `and`.
+         */
+        infix fun and(another: ListeningFilter): ListeningFilter =
+            ListeningFilter { filter.invoke(this, it) && another.filter.invoke(this, it) }
+
+        /**
+         * 进行逻辑 `xor`.
+         */
+        infix fun xor(another: ListeningFilter): ListeningFilter =
+            ListeningFilter { filter.invoke(this, it) xor another.filter.invoke(this, it) }
+
+        /**
+         * 进行逻辑 `nand`, 即 `not and`.
+         */
+        infix fun nand(another: ListeningFilter): ListeningFilter =
+            ListeningFilter { !filter.invoke(this, it) || !another.filter.invoke(this, it) }
+
+        /**
+         * 启动时间监听.
+         */
+        // do not inline due to kotlin (1.3.61) bug: java.lang.IllegalAccessError
+        operator fun invoke(onEvent: MessageListener<T>): Listener<T> {
+            return content(filter, onEvent)
+        }
+    }
+
     /**
      * 无任何触发条件.
      */
     @MessageDsl
-    fun always(onEvent: @MessageDsl suspend T.(String) -> Unit): Listener<T> {
-        return subscriber(onEvent)
+    fun always(onEvent: MessageListener<T>): Listener<T> = subscriber(onEvent)
+
+    /**
+     * 如果消息内容 `==` [equals]
+     */
+    @MessageDsl
+    fun case(
+        equals: String,
+        ignoreCase: Boolean = false,
+        trim: Boolean = true
+    ): ListeningFilter {
+        return if (trim) {
+            val toCheck = equals.trim()
+            content { it.trim().equals(toCheck, ignoreCase = ignoreCase) }
+        } else {
+            content { it.equals(equals, ignoreCase = ignoreCase) }
+        }
     }
 
     /**
-     * 如果消息内容 `==` [equals], 就执行 [onEvent]
+     * 如果消息内容 `==` [equals]
      * @param trim `true` 则删除首尾空格后比较
      * @param ignoreCase `true` 则不区分大小写
      */
     @MessageDsl
     inline fun case(
         equals: String,
-        trim: Boolean = true,
         ignoreCase: Boolean = false,
+        trim: Boolean = true,
         crossinline onEvent: @MessageDsl suspend T.(String) -> Unit
     ): Listener<T> {
         val toCheck = if (trim) equals.trim() else equals
-        return content({ toCheck.equals(if (trim) it.trim() else it, ignoreCase = ignoreCase) }, onEvent)
+        return content({ (if (trim) it.trim() else it).equals(toCheck, ignoreCase = ignoreCase) }, {
+            onEvent(this, this.message.toString())
+        })
     }
 
     /**
-     * 如果消息内容包含 [sub], 就执行 [onEvent]
+     * 如果消息内容包含 [sub]
      */
     @MessageDsl
-    inline fun contains(sub: String, crossinline onEvent: @MessageDsl suspend T.(String) -> Unit): Listener<T> = content({ sub in it }, onEvent)
+    fun contains(sub: String): ListeningFilter =
+        content { sub in it }
 
     /**
-     * 如果消息的前缀是 [prefix], 就执行 [onEvent]
+     * 如果消息内容包含 [sub]
+     */
+    @MessageDsl
+    inline fun contains(
+        sub: String,
+        ignoreCase: Boolean = false,
+        trim: Boolean = true,
+        crossinline onEvent: MessageListener<T>
+    ): Listener<T> {
+        return if (trim) {
+            val toCheck = sub.trim()
+            content({ it.trimStart().contains(toCheck, ignoreCase = ignoreCase) }, {
+                onEvent(this, this.message.toString().trim())
+            })
+        } else {
+            content({ it.contains(sub, ignoreCase = ignoreCase) }, {
+                onEvent(this, this.message.toString())
+            })
+        }
+    }
+
+    /**
+     * 如果消息的前缀是 [prefix]
+     */
+    @MessageDsl
+    fun startsWith(
+        prefix: String,
+        trim: Boolean = true
+    ): ListeningFilter {
+        val toCheck = if (trim) prefix.trim() else prefix
+        return content { (if (trim) it.trim() else it).startsWith(toCheck) }
+    }
+
+    /**
+     * 如果消息的前缀是 [prefix]
      */
     @MessageDsl
     inline fun startsWith(
         prefix: String,
         removePrefix: Boolean = true,
+        trim: Boolean = true,
         crossinline onEvent: @MessageDsl suspend T.(String) -> Unit
-    ): Listener<T> =
-        content({ it.startsWith(prefix) }) {
-            if (removePrefix) this.onEvent(this.message.toString().substringAfter(prefix))
-            else onEvent(this, this.message.toString())
+    ): Listener<T> {
+        return if (trim) {
+            val toCheck = prefix.trim()
+            content({ it.trimStart().startsWith(toCheck) }, {
+                if (removePrefix) this.onEvent(this.message.toString().substringAfter(toCheck).trim())
+                else onEvent(this, this.message.toString().trim())
+            })
+        } else {
+            content({ it.startsWith(prefix) }, {
+                if (removePrefix) this.onEvent(this.message.toString().removePrefix(prefix))
+                else onEvent(this, this.message.toString())
+            })
         }
+    }
 
     /**
-     * 如果消息的结尾是 [suffix], 就执行 [onEvent]
+     * 如果消息的结尾是 [suffix]
      */
     @MessageDsl
-    inline fun endsWith(suffix: String, crossinline onEvent: @MessageDsl suspend T.(String) -> Unit): Listener<T> =
-        content({ it.endsWith(suffix) }, onEvent)
+    fun endsWith(suffix: String): ListeningFilter =
+        content { it.endsWith(suffix) }
 
     /**
-     * 如果是这个人发的消息, 就执行 [onEvent]. 消息可以是好友消息也可以是群消息
+     * 如果消息的结尾是 [suffix]
      */
     @MessageDsl
-    inline fun sentBy(qqId: Long, crossinline onEvent: @MessageDsl suspend T.(String) -> Unit): Listener<T> =
-        content({ sender.id == qqId }, onEvent)
+    inline fun endsWith(
+        suffix: String,
+        removeSuffix: Boolean = true,
+        trim: Boolean = true,
+        crossinline onEvent: @MessageDsl suspend T.(String) -> Unit
+    ): Listener<T> {
+        return if (trim) {
+            val toCheck = suffix.trim()
+            content({ it.trimStart().startsWith(toCheck) }, {
+                if (removeSuffix) this.onEvent(this.message.toString().substringBeforeLast(toCheck).trim())
+                else onEvent(this, this.message.toString().trim())
+            })
+        } else {
+            content({ it.startsWith(suffix) }, {
+                if (removeSuffix) this.onEvent(this.message.toString().removeSuffix(suffix))
+                else onEvent(this, this.message.toString())
+            })
+        }
+    }
 
     /**
-     * 如果是管理员或群主发的消息, 就执行 [onEvent]
+     * 如果是这个人发的消息. 消息可以是好友消息也可以是群消息
      */
     @MessageDsl
-    inline fun sentByOperator(crossinline onEvent: @MessageDsl suspend T.(String) -> Unit): Listener<T> =
-        content({ this is GroupMessage && sender.permission.isOperator() }, onEvent)
+    fun sentBy(qqId: Long): ListeningFilter =
+        content { sender.id == qqId }
 
     /**
-     * 如果是管理员发的消息, 就执行 [onEvent]
+     * 如果是这个人发的消息. 消息可以是好友消息也可以是群消息
      */
     @MessageDsl
-    inline fun sentByAdministrator(crossinline onEvent: @MessageDsl suspend T.(String) -> Unit): Listener<T> =
-        content({ this is GroupMessage && sender.permission.isAdministrator() }, onEvent)
+    inline fun sentBy(qqId: Long, crossinline onEvent: MessageListener<T>): Listener<T> =
+        content({ this.sender.id == qqId }, onEvent)
 
     /**
-     * 如果是群主发的消息, 就执行 [onEvent]
+     * 如果是管理员或群主发的消息
      */
     @MessageDsl
-    inline fun sentByOwner(crossinline onEvent: @MessageDsl suspend T.(String) -> Unit): Listener<T> =
-        content({ this is GroupMessage && sender.permission.isOwner() }, onEvent)
+    fun sentByOperator(): ListeningFilter =
+        content { this is GroupMessage && sender.permission.isOperator() }
+
+    /**
+     * 如果是管理员或群主发的消息
+     */
+    @MessageDsl
+    inline fun sentByOperator(crossinline onEvent: MessageListener<T>): Listener<T> =
+        content({ this is GroupMessage && this.sender.isOperator() }, onEvent)
+
+    /**
+     * 如果是管理员发的消息
+     */
+    @MessageDsl
+    fun sentByAdministrator(): ListeningFilter =
+        content { this is GroupMessage && sender.permission.isAdministrator() }
+
+    /**
+     * 如果是管理员发的消息
+     */
+    @MessageDsl
+    inline fun sentByAdministrator(crossinline onEvent: MessageListener<T>): Listener<T> =
+        content({ this is GroupMessage && this.sender.isAdministrator() }, onEvent)
+
+    /**
+     * 如果是群主发的消息
+     */
+    @MessageDsl
+    fun sentByOwner(): ListeningFilter =
+        content { this is GroupMessage && sender.isOwner() }
+
+    /**
+     * 如果是群主发的消息
+     */
+    @MessageDsl
+    inline fun sentByOwner(crossinline onEvent: MessageListener<T>): Listener<T> =
+        content({ this is GroupMessage && this.sender.isOwner() }, onEvent)
+
+    /**
+     * 如果是来自这个群的消息
+     */
+    @MessageDsl
+    fun sentFrom(groupId: Long): ListeningFilter =
+        content { this is GroupMessage && group.id == groupId }
 
     /**
      * 如果是来自这个群的消息, 就执行 [onEvent]
      */
     @MessageDsl
-    inline fun sentFrom(id: Long, crossinline onEvent: @MessageDsl suspend T.(String) -> Unit): Listener<T> =
-        content({ if (this is GroupMessage) group.id == id else false }, onEvent)
+    inline fun sentFrom(groupId: Long, crossinline onEvent: MessageListener<T>): Listener<T> =
+        content({ this is GroupMessage && this.group.id == groupId }, onEvent)
+
+    /**
+     * 如果消息内容包含 [M] 类型的 [Message]
+     */
+    @MessageDsl
+    inline fun <reified M : Message> has(): ListeningFilter =
+        content { message.any { it::class == M::class } }
 
     /**
      * 如果消息内容包含 [M] 类型的 [Message], 就执行 [onEvent]
      */
     @MessageDsl
-    inline fun <reified M : Message> has(crossinline onEvent: @MessageDsl suspend T.(String) -> Unit): Listener<T> =
-        subscriber { if (message.any { it::class == M::class }) onEvent(this, this.message.toString()) }
+    inline fun <reified M : Message> has(crossinline onEvent: MessageListener<T>): Listener<T> =
+        content({ message.any { it::class == M::class } }, onEvent)
+
+    /**
+     * 如果 [filter] 返回 `true`
+     */
+    @MessageDsl
+    fun content(filter: T.(String) -> Boolean): ListeningFilter =
+        ListeningFilter(filter)
 
     /**
      * 如果 [filter] 返回 `true` 就执行 `onEvent`
      */
     @MessageDsl
-    inline fun content(crossinline filter: T.(String) -> Boolean, crossinline onEvent: @MessageDsl suspend T.(String) -> Unit): Listener<T> =
-        subscriber { if (this.filter(message.toString())) onEvent(this, this.message.toString()) }
+    inline fun content(crossinline filter: T.(String) -> Boolean, crossinline onEvent: MessageListener<T>): Listener<T> =
+        subscriber {
+            if (filter(this, it)) onEvent(this, it)
+        }
 
     /**
      * 如果消息内容可由正则表达式匹配([Regex.matchEntire]), 就执行 `onEvent`
      */
     @MessageDsl
-    inline fun matching(regex: Regex, crossinline onEvent: @MessageDsl suspend T.(String) -> Unit) {
+    fun matching(regex: Regex): ListeningFilter =
+        content { regex.matchEntire(it) != null }
+
+    /**
+     * 如果 [filter] 返回 `true` 就执行 `onEvent`
+     */
+    @MessageDsl
+    inline fun matching(regex: Regex, crossinline onEvent: MessageListener<T>): Listener<T> =
         content({ regex.matchEntire(it) != null }, onEvent)
-    }
 
     /**
      * 如果消息内容可由正则表达式查找([Regex.find]), 就执行 `onEvent`
      */
     @MessageDsl
-    inline fun finding(regex: Regex, crossinline onEvent: @MessageDsl suspend T.(String) -> Unit) {
-        content({ regex.find(it) != null }, onEvent)
-    }
+    fun finding(regex: Regex): ListeningFilter =
+        content { regex.find(it) != null }
+
 
     /**
      * 若消息内容包含 [this] 则回复 [reply]
      */
     @MessageDsl
-    infix fun String.containsReply(reply: String) =
-        content({ this@containsReply in it }) { this@content.reply(reply) }
+    infix fun String.containsReply(reply: String): Listener<T> =
+        content({ this@containsReply in it }, { reply(reply) })
 
     /**
      * 若消息内容包含 [this] 则执行 [replier] 并将其返回值回复给发信对象.
@@ -254,11 +439,11 @@ class MessageSubscribersBuilder<T : MessagePacket<*, *>>(
      * @param replier 若返回 [Message] 则直接发送; 若返回 [Unit] 则不回复; 其他情况则 [Any.toString] 后回复
      */
     @MessageDsl
-    inline infix fun String.containsReply(crossinline replier: @MessageDsl suspend T.(String) -> Any?) =
-        content({ this@containsReply in it }) {
-            @Suppress("DSL_SCOPE_VIOLATION_WARNING") // false negative warning
-            executeAndReply(replier)
-        }
+    inline infix fun String.containsReply(crossinline replier: @MessageDsl suspend T.(String) -> Any?): Listener<T> =
+        content({ this@containsReply in it }, {
+            @Suppress("DSL_SCOPE_VIOLATION_WARNING")
+            this.executeAndReply(replier)
+        })
 
     /**
      * 若消息内容可由正则表达式匹配([Regex.matchEntire]), 则执行 [replier] 并将其返回值回复给发信对象.
@@ -268,12 +453,11 @@ class MessageSubscribersBuilder<T : MessagePacket<*, *>>(
      * @param replier 若返回 [Message] 则直接发送; 若返回 [Unit] 则不回复; 其他情况则 [Any.toString] 后回复
      */
     @MessageDsl
-    inline infix fun Regex.matchingReply(crossinline replier: @MessageDsl suspend T.(String) -> Any?) {
-        content({ this@matchingReply.matchEntire(it) != null }) {
-            @Suppress("DSL_SCOPE_VIOLATION_WARNING") // false negative warning
-            executeAndReply(replier)
-        }
-    }
+    inline infix fun Regex.matchingReply(crossinline replier: @MessageDsl suspend T.(String) -> Any?): Listener<T> =
+        content({ this@matchingReply.matchEntire(it) != null }, {
+            @Suppress("DSL_SCOPE_VIOLATION_WARNING")
+            this.executeAndReply(replier)
+        })
 
     /**
      * 若消息内容可由正则表达式查找([Regex.find]), 则执行 [replier] 并将其返回值回复给发信对象.
@@ -283,12 +467,11 @@ class MessageSubscribersBuilder<T : MessagePacket<*, *>>(
      * @param replier 若返回 [Message] 则直接发送; 若返回 [Unit] 则不回复; 其他情况则 [Any.toString] 后回复
      */
     @MessageDsl
-    inline infix fun Regex.findingReply(crossinline replier: @MessageDsl suspend T.(String) -> Any?) {
-        content({ this@findingReply.find(it) != null }) {
-            @Suppress("DSL_SCOPE_VIOLATION_WARNING") // false negative warning
-            executeAndReply(replier)
-        }
-    }
+    inline infix fun Regex.findingReply(crossinline replier: @MessageDsl suspend T.(String) -> Any?): Listener<T> =
+        content({ this@findingReply.find(it) != null }, {
+            @Suppress("DSL_SCOPE_VIOLATION_WARNING")
+            this.executeAndReply(replier)
+        })
 
     /**
      * 不考虑空格, 若消息内容以 [this] 开始则执行 [replier] 并将其返回值回复给发信对象.
@@ -304,14 +487,14 @@ class MessageSubscribersBuilder<T : MessagePacket<*, *>>(
      * @param replier 若返回 [Message] 则直接发送; 若返回 [Unit] 则不回复; 其他类型则 [Any.toString] 后回复
      */
     @MessageDsl
-    inline infix fun String.startsWithReply(crossinline replier: @MessageDsl suspend T.(String) -> Any?) {
+    inline infix fun String.startsWithReply(crossinline replier: @MessageDsl suspend T.(String) -> Any?): Listener<T> {
         val toCheck = this.trimStart()
-        content({ it.trimStart().startsWith(toCheck) }) {
-            @Suppress("DSL_SCOPE_VIOLATION_WARNING") // false negative warning
-            executeAndReply {
-                replier(it.removePrefix(toCheck).trim())
+        return content({ it.trim().startsWith(toCheck) }, {
+            @Suppress("DSL_SCOPE_VIOLATION_WARNING")
+            this.executeAndReply {
+                replier(this, it.trim().removePrefix(toCheck))
             }
-        }
+        })
     }
 
     /**
@@ -328,30 +511,36 @@ class MessageSubscribersBuilder<T : MessagePacket<*, *>>(
      * @param replier 若返回 [Message] 则直接发送; 若返回 [Unit] 则不回复; 其他情况则 [Any.toString] 后回复
      */
     @MessageDsl
-    inline infix fun String.endswithReply(crossinline replier: @MessageDsl suspend T.(String) -> Any?) {
+    inline infix fun String.endswithReply(crossinline replier: @MessageDsl suspend T.(String) -> Any?): Listener<T> {
         val toCheck = this.trimEnd()
-        content({ it.endsWith(this@endswithReply) }) {
-            @Suppress("DSL_SCOPE_VIOLATION_WARNING") // false negative warning
-            executeAndReply {
-                replier(it.removeSuffix(toCheck).trim())
+        return content({ it.trim().endsWith(toCheck) }, {
+            @Suppress("DSL_SCOPE_VIOLATION_WARNING")
+            this.executeAndReply {
+                replier(this, it.trim().removeSuffix(toCheck))
             }
-        }
+        })
     }
 
     @MessageDsl
-    infix fun String.reply(reply: String) = case(this) {
-        this@case.reply(reply)
+    infix fun String.reply(reply: String): Listener<T> {
+        val toCheck = this.trim()
+        return content({ it.trim() == toCheck }, { reply(reply) })
     }
 
     @MessageDsl
-    inline infix fun String.reply(crossinline replier: @MessageDsl suspend T.(String) -> Any?) = case(this) {
-        @Suppress("DSL_SCOPE_VIOLATION_WARNING") // false negative warning
-        executeAndReply(replier)
+    inline infix fun String.reply(crossinline replier: @MessageDsl suspend T.(String) -> Any?): Listener<T> {
+        val toCheck = this.trim()
+        return content({ it.trim() == toCheck }, {
+            @Suppress("DSL_SCOPE_VIOLATION_WARNING")
+            this.executeAndReply {
+                replier(this, it.trim())
+            }
+        })
     }
 
     @PublishedApi
     @Suppress("REDUNDANT_INLINE_SUSPEND_FUNCTION_TYPE") // false positive
-    internal suspend inline fun T.executeAndReply(replier: @MessageDsl suspend T.(String) -> Any?) {
+    internal suspend inline fun T.executeAndReply(replier: suspend T.(String) -> Any?) {
         when (val message = replier(this, this.message.toString())) {
             is Message -> this.reply(message)
             is Unit -> {
diff --git a/mirai-demos/mirai-demo-gentleman/src/main/kotlin/demo/gentleman/Main.kt b/mirai-demos/mirai-demo-gentleman/src/main/kotlin/demo/gentleman/Main.kt
index e6a3800da..98cf4a85a 100644
--- a/mirai-demos/mirai-demo-gentleman/src/main/kotlin/demo/gentleman/Main.kt
+++ b/mirai-demos/mirai-demo-gentleman/src/main/kotlin/demo/gentleman/Main.kt
@@ -138,6 +138,10 @@ suspend fun main() {
             }.reply()
         }
 
+        (contains("1") and has<Image>()){
+            reply("Your message has a string \"1\" and an image contained")
+        }
+
         has<Image> {
             if (this is FriendMessage || (this is GroupMessage && this.permission == MemberPermission.ADMINISTRATOR)) withContext(IO) {
                 val image: Image by message